1. Field of the Invention
The present invention relates to a sheet distributing system for distributing recorded sheets discharged from an image recording apparatus, such as a copying machine or a printer, into sheet receiving trays, and more particularly to a sheet distributing system capable of applying post-processes, such as stapling, punching, and binding, to the stacked recorded sheets contained in the trays.
2. Discussion of the Related Art
In a sheet distributing system called a sorter, a sheet transfer path, disposed within a sorter housing, transfers a recorded sheet or sheets discharged from a sheet exit of an image recording unit to a sheet distribution stage. A set of vertically arranged bin trays are provided adjacent to the side of the housing, and is moved toward the sheet distribution stage at the distributing timings of the recorded sheets. With the construction, the sheets are distributed into the bin trays.
In this type of sorter, it is necessary to hold the stack of recorded sheets contained in each bin tray against the disarrangement of them. To this end, a sheet arranging mechanism is usually provided in the sorter (Japanese Patent Application Unexamined Publication Nos. Sho. 64-34855 and Hei. 1-271371).
Usually, post-processing, such as stapling, is applied to the stacked recorded sheets that are sorted and contained in the trays. To realize this, a post-processing unit, such as a stapler is assembled into the sorter, to automatically staple the stacked recorded sheets. This type of sorter is disclosed in Japanese Patent Application Unexamined Publication Nos. Sho. 63-41360 and Sho. 63-252872, and Japanese Patent Application Examined Publication No. sho. 64-302.
The sorter disclosed in Japanese Patent Application Unexamined Publication No. Sho. 63-41360 is constructed such that the stacked recorded sheets, which are distributed into and contained in the bin trays, are transferred into a post-processing tray, and then the stapling process is applied to the stacked recorded sheets contained in the post-processing tray. Because of such a construction, the post-processing tray must be provided in addition to the bin trays, and a transfer means for transferring the stacked recorded sheets to the post-processing tray must be also provided. The use of the additional components and mechanism makes the sorter construction complicated. The stacked recorded sheets, once arranged in the bin trays, may be disarranged when the sheets are transferred from the bin tray to the post-processing tray, possibly making the post-process by the stapler meaningless.
In the sorter as disclosed in Japanese Patent Application Unexamined Publication No. Sho. 63-252872 or Japanese Patent Application Examined Publication No. Sho. 64-302, a stapler is disposed in a location near the sheet distribution stage where the stapler does not interfere with the sheet transfer member. The post-process by the stapler is applied to the stacked recorded sheets being contained in the bin tray (one corner portion of the stacked recorded sheets contained in the bin tray). Accordingly, this type of sorter is free from the disarranging problem of Japanese Patent Application Unexamined Publication No. Sho. 63-41360, but cannot have the function of the dual stapling which staples one side marginal portion of the stacked recorded sheets at two positions.